1. Field of the Invention
The present invention relates to a method and apparatus for providing Downloadable Conditional Access System (DCAS) service and managing the same. In particular the present invention relates to a method and apparatus for management and transmission of a classified conditional access application to provide DCAS service.
This work was supported by the IT R&D program of MIC/IITA [2007-S-007-01, The Development of Downloadable Conditional Access System].
2. Description of Related Art
A Conditional Access System (CAS) is a system that assigns authority to watch fee-based broadcast to only authenticated subscribers. A terminal of the CAS has functions of managing a conditional access key and decoding accessed signal encoded by the conditional access key so as to watch the accessed signal, and the function is referred to as a conditional access module. In a conventional CAS applied to a digital cable broadcast, a conditional access module has been implemented in a cable card form. However, as problems of high cost and inefficient management ability of the cable card is raised, a Downloadable Conditional Access System (DCAS) is suggested. The DCAS safely downloads the conditional access application, namely, conditional access module implemented in software form to an authenticated subscriber terminal, thereby supporting a conditional access service to subscribers and assigning authority to remotely configure or reset a conditional access method to a service operator.
Accordingly, the conditional access module of the conventional CAS that is provided off-line is required to be stored in the DCAS, and also an effective method that can safely download a stored conditional access module to an authenticated terminal is required. That is, an effective storage and transmission method according to a feature of a conditional access application.
Also, the conventional CAS operates in an integrated environment system where a series of functions required to perform the CAS are closely combined with a CAS service operator, such as setting up conditional access module for a terminal, registering a subscriber, paying for fee-based broadcast, and assigning authorization to view a fee-based broadcast.
However, the DCAS manages a conditional access module received from a CAS service provider and downloads the conditional access module to an authenticated terminal, and registers the terminal as a subscriber. Then, the CAS provider performs a subscribing and payment process for the fee-based broadcast, and assigns authorization to view a fee-based broadcast. In this case, the CAS service operator is required to minimize an interface with the DCAS to have security and autonomy.